Walking mechanism assembly



March 17, 1910 K. 1.. aARbEN ETAL 3,500,945

WALKING MECIQNISM ASSEMBLY Filed May 1, 1968 4 Sheets-Sheet 1 9. INVENTORS 6H KENNETH L. Bmzosu,

DANIEL 3'. Pulls-Y E owm \Msmmsv ATTORNEY S March 17, 1970 K. L. BARDEN ETAL WALKING MECHANISM ASSEMBLY Filed May 1. 1968 itg-z 4 Sheets-Sheet 2 INVENTORS KENNETH L. BARDGN, DANIEL J. FunE-Y Eowm W.5ANKEY masmfi emmik (foam web ATTORNEYS March 17, 1970 K. L. BARDEN ETAL WALKING MECHANISM ASSEMBLY Filed May 1, 1968 4 Sheets-Sheet 5 March 17, 1970 K. L. BARDEN ETAL WALKING MECHANISM ASSEMBLY United States Patent O 3,500,945 WALKING MECHANISM ASSEMBLY Kenneth L. Barden, Daniel J. Fnrey, and Edwin W.

Sankey, Marion, Ohio, assignors to Marion Power Shovel Company, Inc., Marion, Ohio, a corporation of Delaware Filed May 1, 1968, Ser. No. 725,627 Int. Cl. 362d 57/02 US. Cl. 180-8 Claims ABSTRACT OF THE DISCLOSURE A walking mechanism subassembly for dragline machines, wherein the assembly includes a rigid frame having spaced front and back sections, with a shaft having an eccentric portion journalled at its ends in the frame. A walking arm has an antifriction bearing mounted on the eccentric and is coupled to a Walking shoe and anchored to the frame. A drive from the shaft is also carried by the assembly frame. Means are provided for attaching the subassembly as a unit to the dragline machine rotatable frame.

BACKGROUND OF THE INVENTION This invention relates to walking structures for heavy equipment, and more particularly to walking structures of the general type used on very large dragline machines.

As the demand grew for larger dragline machines, a point was reached where it was not longer feasible to mount, or move, the machines on conventional transportating, or propelling, means. Resort was made to socalled walkers to move the machines from place to place. these are shoes, or pontoons, mounted on cranks which lift one side of the tub on which the machine is mounted, slide the tub along the ground, and lower the raised side. The shoes are then raised, moved forward and lowered to complete the cycle. Such mechanism is shown in detail in Patent No. 3,078,941.

Since the first use of walking mechanism, the machines have increased tremendously in size and weight. This has caused great difficulty in the manufacture, machining, assembly, and maintenance of the walking mechanism. As shown in Patent No. 3,078,941, it has been customary to mount the shoes on walking arms carried by cranks supported in overhung, outboard crank bearings. This arrangement leaves the crank projecting unsupported beyond the machine, with walking loads being imposed on the unsupported ends of the cranks. Thus, crank deflections will greatly affect the alignment of the propel machinery.

In order to avoid crank deflection, extremity large, heavy cranks are being used. Many are so large that the crank bearings cannot be machined in the shop, but must be machined in the field, at the assembly site. Serious problems arise because of this, not the least of which is the problem of alignment of shafts, gears, etc.

The problems arising from the above factors are not fully understood until it is realized that the weight imposed will be supported both inboard and outboard of the millions of pounds, and crank bearings may be 10 feet in diameter. It is the shear enormity of size and weight that cause the problems.

SUMMARY OF THE INVENTION It is the general object of the present invention to provide walking mechanism which will overcome many of the above set out problems.

A more specific object of the invention is to provide walking mechanism Which will be in the form of a subassembly attachable to the rotatable frame as a unit.

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Another object is the provision of such mechanism wherein the shaft upon which the weight load is imposed will be supported both inboard and outboard of the area of load.

A further object is to provide Walking mechanism having the walking crank and its entire propel machinery mounted in a single subassembly, so that structural deflections have little effect upon the propel machinery alignment.

Yet another object of the invention is to provide a walking mechanism wherein the usual eccentrically loaded crank is replaced by an eccentrically bored walking arm.

Other objects of the invention will become apparent from the following description of one practical embodiment thereof, when taken in conjunction with the drawings which accompany, and form part of, this specification.

BRIEF DESCRIPTION OF THE DRAWINGS FIGURE 1 is a side elevation of a walking mechanism embodying the principles of the present invention, shown in place on a dragline;

FIGURE 2 is a top plan view of the structure shown in FIGURE 1;

FIGURE 3 is a vertical transverse section through the walking mechanism, taken on the line 3-3 of FIG- URE 1;

FIGURE 4 is a vertical, longitudinal section taken on the line 4-4 of FIGURE 3; and

FIGURE 5 is another transverse section, taken on the line 55 of FIGURE 1, illustrating particularly the manner of attachment of the unit to the machine rotatable frame.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in detail, there is shown a portion of a dragline machine 1, with parts of the tub 2 and rotatable frame 3 being illustrated. The improved walking mechanism assembly 4 is shown carried by the rotatable frame. The walking mechanism includes a frame 5, connected to the rotatable frame, an eccentric shaft 6 journalled in the frame, propel mechanism 7, a walking arm 8 and a shoe 9. It will be understood that similar walking mechanism will be provided on both sides of the machine for simultaneous operation.

The frame 5 of the subassembly is fabricated from a front section 10, a back section 11, and end sections 12 and 13, joined together to form a rigid unit. The specific construction of the frame, aside from the features to be described, is not important. It is of importance that the several sections be joined to hold the front and back sections in spaced, parallel relation, and that the center of the frame, as viewed from above, be open, as in 14.

The front and back sections have axially aligned hubs 15 and 16 which house bearings 17 and 18 to journal a shaft 19. The shaft is relatively short, extending only the width of the frame. It Will be noted that the shaft has no overhung portion, but is supported by the bearings at each end. Centrally on the shaft there is an eccentric 20, fixed to the shaft to rotate with it. Final drive gears 21 are bolted to opposite sides of the eccentric, and the shaft, eccentric and gears rotate as a unit.

The walking arm 8 is shaped as a bell crank, and has a central opening 22 to encircle the eccentric 20. A bearing 23 is mounted on the eccentric to receive the walking arm and assure free movement of the eccentric within the walking arm. Rotation of the eccentric will cause the walking arm to rise and fall.

One limb 24 of the walking arm is coupled to the shoe 9 by means of a ball joint 25, so that the shoe is free for universal movement to permit it to seat firmly upon the ground regardless of the contour. The other limb 26 is pivotally connected by a pin 27 to one end of a link 28 which has its other end pivotally connected to an anchor pin 29 seated in openings 30 in the front and back sections of the frame. By linking the walking arm to the anchor pin, the rise and fall of the arm under the influence of the eccentric imparts a horizontal moment to the connection of the arm to the shoe 9 to cause the connection to move in an orbital path and provide the required stepping movement of the shoe 9. The precise stepping motion forms no part of the present invention. The important factors are the mounting and anchoring of the walking arm within the frame 5.

The entire drive for the eccentric is also shown carried by the frame 5, although this may not always be the arrangement. A shaft 31 is mounted in journals 32 to lie above and parallel to, the shaft 19. Shaft 31 carries gears 33, in mesh with gears 21, and a gear 34. Gear 34 is part of a gear train 35 from a drive motor 36 to the final gears 21. The gears of the train are carried by shafts 37 and 38, mounted in bearings 39 and 40 at the top of the frame. Motor 36 is fixed to a platform 41 on the end section 12 of the frame.

The frame, walking arm and its propel means are designed as a subassembly to be mounted as a unit on the rotatable frame of the dragline machine. To this end, the back section 11 of the frame carries sleeves which form pin eyes 42 at the top and bottom at each end. These are adapted to be inserted between mounting ears 43 projecting from the rotatable frame 3. Mounting pins 44 are put through openings in the ears and through the pin eyes to tie the subassembly to the rotatable frame. Thus, the subassembly will be securely attached adjacent each corner to the rotatable frame. The back frame section 11 may be rearwardly extended at its middle, as at 45, to bear against the rotatable frame to further brace and support the assembly when it is mounted on the dragline frame.

The provision of the walking mechanism as a subassembly eliminates the requirement of complete rigidity between the walking mechanism and the rotatable frame, for there is no overhung portion of the drive taking the weight of the machine. The shaft 19 upon which the weight is imposed is journalled at both ends and the weight is carried between the ends. Therefore, the various elements of the walking mechanism, and particularly the shaft, can be made much smaller with all of the parts being machined at the shop prior to shipment to the field for assembly to the rotatable frame. Where the entire propel drive is carried by the frame, the only connection between the subassembly and the rotatable frame is by means of the mounting pins 44. The arrangement completely eliminates the need for alignment with parts of the mechanism on the rotatable frame. Obviously, repair or replacement of the unit can be accomplishedwith a minimum of expense. The ultimate result is a much lighter and freer operating mechanism, with the respective walking mechanisms on opposite sides of the dragline machine being wholly independent of one another. Stresses and structural deflections are carried from the walking mechanism units to the rotatable frame through the mounting pins, entirely without effect upon the operating mechanisms.

We claim:

- 1. A walking mechanism subassembly for heavy equipment having a machine frame comprising, an assembly frame including spaced front and back sections, a shaft having ends journalled in the front and back assembly sections, the shaft having an eccentric portion, a walking arm rotatably mounted on the eccentric portiOn of the shaft, 3. shoe connected to the walking arm, means connected to the walking arm and the assembly frame to anchor the walking arm, and means for attaching the assembly frame to the machine frame.

2. A walking mechanism subassembly as claimed in claim 1 wherein, there are means to drive the shaft carried by the assembly frame.

3. A walking mechanism subassembly as claimed in claim 2 wherein, the connection between the walking arm and shoe includes a universal joint.

4. A walking mechanism subassembly as claimed in claim 1 wherein, the means for attaching the assembly frame to the machine frame is located at the corners of the back assembly frame section.

5. A walking mechanism subassembly for heavy equipment having a machine frame comprising, an assembly frame having horizontally spaced back and front sections joined at their ends, aligned bearings in the front and back assembly frame sections, a shaft journalled in the bearings, the shaft having an eccentric portion lying intermediate the bearings, a bearing on the eccentric portion, a walking arm having an opening seating the bearing on the eccentric portion of the shaft, a shoe connected to the walking arm below the assembly frame, means connected to the walking arm and the assembly frame to anchor the walking arm, and means for attaching the assembly frame to the machine frame.

6. A walking mechanism subassembly as claimed in claim 5 wherein, there are means to drive the shaft carried by the assembly frame.

7. A walking mechanism subassembly as claimed in claim 5 wherein, the walking arm has a downward extension connected to the shoe by a universal joint.

8. A walking mechanism subassembly as claimed in claim 7 wherein, the means connecting the walking arm to the assembly frame includes a link pivotally connected to the walking arm to one side of the shaft, and an anchor pin having its ends connected to the front and back assem- ;bly frame sections and connected to the link intermediate the front and back assembly frame sections.

9. A walking mechanism subassembly as claimed in claim 5 wherein, final drive gears are carried by the shaft intermediate the bearings journalling the shaft, and there are means to drive the gears.

10. A walking mechanism subassembly as claimed in claim 9 wherein, the means to drive the gears includes a motor mounted on the assembly frame, and a gear train carried by the assembly frame intermediate the motor and the final gears.

References Cited UNITED STATES PATENTS 2,179,765 11/1939 Stock 180-8 3,078,941 2/1963 Baron et al. l-8 3,249,168 5/1966 Klein et al. 8 3,265,145 8/1966 Beitzel 1808 3,375,892 4/1968 Kraschnewski 180-8 LEO FRIAGLIA, Primary Examiner 

